DAVID Potter will never forget the first time his prison cell door slammed shut.

DAVID Potter will never forget the first time his prison cell door slammed shut.

As a former detective constable and convicted rapist, the father-of-two knew his time in the top security Frankland prison in Durham would be a living hell.

Sentenced to nine years he was eventually released on parole after five - but the fact that he was an innocent man made it seem like a lifetime.

Yesterday Mr Potter's 1998 conviction for the rape of an exgirlfriend was quashed by the court of appeal.

Now he could be in line for #500,000 compensation and a police medical pension or a return to work.

Today the 50-year-old from Huyton tells how:

. He broke down as the doors slammed shut on his small cell on the first night of his sentence.

. Three years into his jail term he was moved into adjoining cells with serial killer Dr Harold Shipman.

. He thought about taking his own life after hitting rock bottom.

. Prison staff had to keep him away from other prisoners over fears he would be attacked.

. His conviction ruined his relationship with one of his daughters

. He turned detective and, with the help of his mother and father, began to clear his name.

Mr Potter, now living in the south of England, said: "Only someone who has been falsely accused will know how I felt that first night in prison.

"I was alone and terrified. I was an ex-bobbie who had been found guilty of rape - in the eyes of other prisoners there can be nothing worse.

"When the guilty verdict came in I just went into shock. During the trial I was portrayed as an evil rapist who did sickening things to my ex-girlfriend.

"I always thought I would walk free and go back to my job with the police.

"This woman had made false claims. I had left her as she clearly had problems and was not even in contact with her when she said I raped her."

During his prison ordeal he suffered severe depression. But he was determined to help others, and taught fellow prisoners.

"In prison thoughts of suicide were dominant," he said.

"But I decided to make the best of it and taught other prisoners."

Mr Potter, who worked asa detective for Merseyside police's regional crime squad, was in prison when he started examining the papers of the court case which led to his conviction in 1998.

He had met the Huyton woman who became his accuser in late 1990 and they dated until Easter 1991.

In 1998 she went to police and claimed that in 1994 he bound, gagged and raped her at his home before sexually assaulting her with a truncheon.

Mr Potter, a divorcee, was found guilty at Liverpool crown court, and the judge, Mr Justice Douglas Brown, said at the time: "Your victim was a most vulnerable and defenceless woman."

The conviction destroyed his relationship with one of his daughters, who refused to have anything to do with her father.

Now Mr Potter longs to rekindle that relationship and yearns to be reunited with the daughter he feared would never speak to him again.

During the trial Mr Potter's legal team did not look into the background of his accuser, who is now aged 42.

With the help of his 74-year-old parents, and Wirral solicitor Tony Nelson they tracked downa headmaster who had dated his accuser before Mr Potter allegedly raped her.

They found him - and he eventually agreed to be interviewed by Merseyside police. His evidence was the eventual key to Mr Potter's freedom.

Yesterday at the court of appeal in London, the headmaster ws granted anonymity and referred to only as Mr X.

Lord Alex Carlisle, representing Mr Potter, told the hearing: "After a period of some investigation, lasting two to three years, Mr X provided new evidence which we bring before the court today."

David Steer QC, representing the Crown, said he accepted that, had the jury at the original trial heard Mr X's evidence, the outcome could have been " significantly different".

The judge, Lord Justice Scott Baker, then said: "Had Mr X been called to give evidence the judge in the trial would have allowed that evidence to be given. On that basis the conviction of Mr Potter is unsafe and the conviction is quashed."

As the judge made his comments Mr Potter wept and afterwards was hugged by his family and friends, many of whom had travelled down from Merseyside.

He said: "Hearing that decision made me just want to fall to the ground in a heap and I just could not contain my emotions.

"It was six years ago that I went to prison and at times I felt like dying. I just hope I can put my life back together."

He stressed: "I do not holda grudge in the way anything was investigated."

Mr Potter's father, Terry, of Huyton, said: "Both Doreen and I knew my son was innocent and believed in him from day one.

"I just hope he has a happy life and I am so thankful that he is now cleared of anything and that this burden has been lifted."

Mr Nelson said he and his client Mr Potter would discuss their options in the coming weeks.

"My instinct told me that David was innocent and it has been a long hard road to have the conviction quashed.

"I spoke to Mr X on several occasions befoe he gave evidence, but when he did, we were all hopeful this day would happen."

"There will be discussions about compensation and a medical police pension but nothing has been set in stone."

My life as Dr Death's neighbour>>>>

My life as Dr Death's neighbour>

THREE years into David Potter's prison sentence he was left stunned when Britain's biggest serial killer was brought into an adjoining cell.